theorem :: BORSUK_5:62

(].-infty,1.[ \/ ].1,+infty.[) /\ (((].-infty,2.] \/ (IRRAT (2,4))) \/ {4}) \/ {5}) = (((].-infty,1.[ \/ ].1,2.]) \/ (IRRAT (2,4))) \/ {4}) \/ {5}